Augmented reality is the technology that deals with the overlay of virtual information on top of the physical world, usually as seen through a lens or electronic device.
The most common method for utilizing AR technology is via an external device such as a camera or smart-phone. The device creates a digital overlay over the screen where the camera records the physical world. While a static digital overlay is common for devices, (such as camera settings) more advanced techniques can add more functionality to the device, such as reading the environment, recognizing faces/shapes, global position, device rotation, and other criteria that allow the overlay to 'project' information seemingly onto the real world object.
Head mounted displays are another common method which uses overlays information onto a screen over a lens that covers the eyes, such as eyeglasses. The only different here is that the screen is detached from the external device.
Projection display is a method in which a projector can identify objects and then instead of sending the information to an overlay on a device, will instead project the image directly onto the surface in question. This is usually used in conjunction with spatial augmented reality.
Augmented Reality in Pop Culture
Pokemon Go! Was released in 2016, a game that Augmented reality is fundamental to.